CVE-2026-6279 (GCVE-0-2026-6279)

Vulnerability from cvelistv5 – Published: 2026-05-21 04:27 – Updated: 2026-05-21 04:27
VLAI?
Title
Avada (Fusion) Builder <= 3.15.2 - Unauthenticated Remote Code Execution via PHP Function Injection via 'render_logics' Shortcode Attribute via Widget AJAX Handler
Summary
The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2. This is due to the `wp_conditional_tags` case in `Fusion_Builder_Conditional_Render_Helper::get_value()` passing attacker-controlled values from a base64-decoded JSON blob directly to `call_user_func()` without any allowlist validation. This is exploitable by unauthenticated attackers through the `fusion_get_widget_markup` AJAX endpoint, which is registered for non-privileged (unauthenticated) users via `wp_ajax_nopriv_fusion_get_widget_markup`. The endpoint is protected only by a nonce (`fusion_load_nonce`), but this nonce is generated for user ID 0 and is deterministically exposed in the JavaScript output of any public-facing page containing a Post Cards (`[fusion_post_cards]`) or Table of Contents (`[fusion_table_of_contents]`) element. This makes it possible for unauthenticated attackers to execute arbitrary code on affected sites.
Severity ?
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Assigner
References
Impacted products
Vendor Product Version
themefusion Avada (Fusion) Builder Affected: 0 , ≤ 3.15.2 (semver)
Create a notification for this product.
Credits
Tin Pham Trong Pham Hao Ngo
Show details on NVD website
To clipboard 

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          "vendor": "themefusion",
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          "type": "finder",
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          "value": "Trong Pham"
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      "timeline": [
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          "time": "2026-04-15T07:44:24.000Z",
          "value": "Vendor Notified"
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          "time": "2026-05-20T15:45:14.000Z",
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    "dateReserved": "2026-04-14T14:08:39.242Z",
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  }
}


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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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